Siftproof bag



April 27, 1937. A. J. STERLING SIFTPROOF BAG Filed July 2, 1932 2 Sheets-Sheet 1 INEENT ATTORNEY April 27, 1937'. A. J. STERLING 2,078,467"

SIETFBOOF BAG 7 Filed July 2, 1952 2 Sheets-Sheet 2 INVENTO ATTORNEY Patented Apr. 27, 1937 UNITED STATES PATENT OFFICE. 1

SIFTPROOF BAG.

Albert J. Sterling, Brooklyn, N. Y.

Application July 2, 1932, Serial No. 620,567

15 Claims.

The general object of this invention is to produce a bag, rectangular in cross-section, capable of standing squarely on its bottom, and having its bottom walls so arranged as to be sift-proof and air-tight.

This invention further includes the provision of a bag having an inner ply of waterproof material and an outer ply of non-waterproof material in which the bottom folds are so arranged as to 10 provide sealing adhesion between folds of the waterproof material independently of sealing adhesion between folds of the non-waterproof material.

This invention further includes the provision 15 of a bag in the-bottom of which the flaps of each pair of flaps mutually overlap, one on the other. I

This invention further includes the provision, in a multi-ply, square bottom bag, of means for mutually and adhesively joining pairs of flaps of each ply and also adhesively joining the pairs of flaps of the several plies.

These and other objects will appear'in the following detailed description when considered in 25 connection with the accompanying drawings, in

which:

Figure 1 represents the bag blank before the bottom is folded;

Figure 2 represents the first stage of the bot- 30 tom-folding operation;

Figure 3 represents the second stage, Figure 4 the third stage and Figure 5 is a view of the completely folded bottom; c

Figure 6 is a view similar to Figure 1 but di- 35 rected to the ultimate formation of a different type of bottom;

Figure 7 shows the preliminary folding operation on the blank of Figure 6;

Figure 8 shows the second step in the produc- 40 tion of this bottom; v

Figure 8A is a detail of a piece of material inserted to provide siftproof qualities in this bottom;

-Figure 9 represents the next to the last stage of the completion of the bottom; and

" Figure 10 shows the bottom completed.

Referring to the form of Figures 1 5 inclusive I isa tube composed of an outer paperply 2 and an inner glassine or waterproof ply 3. The

50 upper end of the tube is cut away as at l to provide a gripping point for opening the bag.

Theoppos'ite end of the bag is slit along. lines 1 andl on one face and along lines 8 and 8' on the other." These slits extend through both the 55 innerand outer plies of the bag. Score lines 9 and Ill extend across both the faces and the sides of the tube, and are spaced longitudinally of the tube away from the inner'ends of the slits. It will be noted that a flap l I is provided between the slits I and 'l' of one face of the tube and a similar flap II is provided between the slits 8 and 8 in the opposite face. The material of the outer ply is extended between opposed slits I and 8 to form a. long flap I 2. 0n the opposite side the material of the outer ply extends between slits 1 and 8' to form a short flap B. The inner ply on the side adjacent the long flap I2 forms a shorter flap M which is otherwise coextensive with the long flap l2. 0n the opposite side the inner ply is extended intermediate the slits 1' and 8' to form along flap I 5 of the same size as the oppositely disposed long flap l2 of the material of the outer ply. Perforations [6 are provided through both inner and outer plies and located intermediate the slits and the intersection of the faces and sides of the tube. Longitudinally of the tube these perforations are placed'intermediate the inner end of the slits and the bottom end of the tube.

In forming the bag bottom the short flap ll of inner ply material is folded downward into the plane of the score line 9 and along that line as indicated in Figure 2. The long flap l5 of inner ply material is then similarly folded upon the short flap l4 and is pasted thereto throughout the overlapping area or at least completely around the outer margins of the overlapping area. The short flap i3 of outer ply material is then folded down upon the long flap iii of in- V ner ply material, the condition of the bag at this point being indicated in Figure 3. The next step is to fold the long flap l2 of outer ply ma-' terial over the short flap l3 and pasting the flaps l2 and [3 together in a manner similar to that used on the flaps of inner material I and i5. The bag is now in the condition indicated in Figure 4.

With the bag bottom in the condition shown in Figure 4, paste is applied over the outer margins of the flaps II and H. These flaps are composed of both the inner and outer plies which preferably will have been laminated together in the course of formation of the tube. The area to which the paste is applied is extended to include a portion of the folded flaps l2 and I3 as indicated-at I! in Figure 4. This pasting is, of

course, duplicated on both of the flaps II. It

the perforations it previously mentioned.

The closing of the bag is completed by folding both of the flaps II in any sequence over the flaps l2 and I3. When this is done the pasted area I! on the flaps l2 and I3 comes over the perforationsv l6 and paste is squeezed therethrough, thus securing the several plies together in siftproof and air-tight condition. This bottom is securely locked against the egress of .pulverulent material or of gas or the ingress of air and moisture, and is so arranged that the glassine. plies are pasted only to glassine and the paper plies only to paper. This is a most important feature of this invention.

It is within the scope of this invention toseparate the inner and outer plies of the flaps II and H and utilize the inner ply flaps to make an absolutely complete closure of inner ply material upon which is superimposed an absolutely complete closure of outer material.

In Figures 6-10 inclusive is shown a modification of the closure above described. In Figure 6 the tube is designated as 20, the outer material as 2|, the inner material as 22, the pairs of slits as 23-23' and 24-24 respectively. The

pair of flaps 25 and 25' on the faces of the tube are of equal length as are the flaps 26 and 26' on the sides of the tube. The inner and outer ply materials are co-extensive in each .of the flaps. The closure is formed by folding down side flaps 21 and 21' of inner material along a.

score line 30 and into the plane of said line. A piece of material 3| comprising a ply of pa.-

} per 32 laminated to a ply of glassine 33 is applied to the folded glassine flaps 21 and 21' with the glassine surface 33 pasted to the glassine flaps and overlapping their meeting line. The side flaps 26 and 2 6 of paper are then folded down upon the previously folded glassine flaps and the inserted piece 3! and are pasted to the upper paper surface 32 of the inserted piece 3l. The face flaps 25 and 25 consisting of both inner and outer plies preferably laminated together are then folded down in any desired sequence upon the other flaps. The pasting of these flaps is precisely similar to that described in connection with the flaps H indicated in Figure 4 and similarly indicated in Figure 9,

and includes the provision of perforations l0 located and proportioned in a manner precisely similar to that of the perforations l5, Figures 1-5 inclusive.

As stated in connection with the form of Figures 1-5 the glassine included in the flaps 25 serted strip it may be unnecessary to paste the glassine flaps together. It will be understood that this invention is not restricted to the use of paper and glassine. Any suitable materials may be used and it is not even requisite that the outer ply be of a different material than the inner ply. In the form of Figures 1-5 the outer flaps l2 and i3 can be pasted to the inner flaps I l and [5 as well as to each other, and the flaps II and II as indicated in Figure 4 can be covered over their entire surface with paste, this surface being all that portion of the flaps lying beyond the score line 9.

This invention'is not to be limited by the precise details of disclosure, which is to be taken as illustrative merely. The only'limitation to be placed upon this invention is that set forth in the subjoined claims which are to be broadly construed.

I claim:

1. In a multi-ply gusseted bag slit and-scored for the formation of a square bottom; a pairof flaps of inner material folded inwardly from the gusseted sides; a pair of flaps of outer material similarly folded over the previously folded flaps of inner material; and adhesive connections between the flaps of eachpair.

2. In a multi-ply gusseted bag slit and scored for the formation of a square bottom; a flap of inner material on each gusseted side, the combined length of both flaps being greater than the bag width; similarly proportioned flaps of outer material; the inner flaps being folded together in overlapped relation and the outer flaps being similarly folded overthe previously folded inner flaps.

3. A bag as in claim 2 in which the unequal flaps of one ply are respectively adjacent oppositely unequal flaps of another ply.

4. A bag having a square bottom; equal flaps on two opposed sides of said bottom; unequal flaps on the other opposed sides, the shorter of said unequal flaps being folded under the longer of said unequal flaps and said equal flaps being folded over the unequal flaps.

5. A bag having inner and outer plies and a square bottom; equal flaps on two opposed sides of said bottom, the materials of the several plies being coextensive in said flaps; the outer ply forming a long flap on one of the other opposed sides and a short flap on the side opposed to it; the inner ply having a short flap adjacent the long flap of the outer ply and having a long flap adjacent the short flap of the outer ply; the long flap of the inner ply being folded over the short flap of the inner ply, the short flap of the outer ply being folded over both flaps of said inner ply; the long flap of the outer ply being folded over the short flap of the outer ply; and both plies of each of said equal flaps being folded over all of said other flaps.

6. A bag formed from a tube, both faces of said tube being slit at one end of the tube along parallel lines in the direction of the tube length and slightly spaced from the tube edges; a square bottom including on opposite sides thereof the slit faces of said tube, the portion of the tube faces intermediate each pair of slits forming equal flaps; a long flap at one end of said square 1 bottom including all the material from one slit of one tube face to the adjacent slit in the opposed tube face; a short flap on the side of the square bottom opposite the long flap, said short flap including all the material from the other slit of the first-named face to the corresponding slit of the second-named face.

7. A bag as set forth in claim 4 in which the long flap is folded over the short flap and both of said equal flaps are folded over the long and short flaps.

8. A bag formed from a tube length, said tube length having inner and outer plies, the materials of both plies in each face of the tube being slit at one end of the tube along parallel lines in the direction of the tube length and slightly spaced from the tube edges; a square bottom including on opposite sides thereof the slit faces of said tube, the portion of the tube faces intermediate each pair of slits forming equal flaps; the material of the outer ply forming a long flap at one end of said square bottom and including all of the material of said outer ply between one opposed pair of slits; the material of the inner ply forming a flap shorter than, but otherwise coextensive with the long flap of the outer ply; a long flap formed from the material of the inner ply at the end of the square bottom opposite the long flap of the outer ply, and a shorter flap of the outer ply at said end and otherwise coextensive with the flap formed by the inner ply.

9. A bag as set forth in claim 6 in which the long flap of the inner ply is folded over the short flap of the inner ply; the short flap of the outer ply is folded over the long flap of the inner ply; the long flap of the outer ply is folded over the short flap of the outer ply and the said equal flaps consisting of both plies are both folded over said other flaps.

10. A bag as disclosed in claim 6 in which the folded lines of the various flaps are spaced longitudinally of the tube length from the inner end of the slits.

11. A gusseted bag slit and scored for the formation of a square bottom and formed of an inner and an outer ply of material; a flap formed from the material of each ply on each of the gusseted sides, the combined length of the flaps of each ply being greater than the bag width.

12. A multi-ply bag, slit and scored for the formation of a square bottom, and being perforated at points intermediate each slitand the adjacent bag side.

13. In a bag haVingIinner and outer plies and provided with a square bottom, said bottom being formed from flaps equal in length on two opposed sides of said bag, the inner ply being provided with a long flap on one of the other opposite sides and having a short flapon the side opposite to it, the outer ply being. provided with a short flap adjacent the long flap of the inner ply and a long flap adjacent the short flap of the inner ply, the long flap of the inner ply being folded over and adhesively secured to the short flap of the inner ply, the long flap of the outer ply being folded over adhesively secured to the short flap of the outer ply, and said equal flaps being folded over all of said other flaps.

14. A bag formed from a tube, both faces of said tube being slit at one end of the tube along parallel lines in the direction of the tube length and slightly spaced from the tube edges, the faces of said tube being provided with perforations located between each slit and the adjacent bag side, a square bottom including on opposite sides thereof the slit faces of said tube, the portion of the tube faces intermediate each pair of slits.

forming equal flaps; a long flap at one endof said square bottom including all thematerial from the slit of one tube face to the adjacent slit in the opposed tube face; the short flap on the side of the square bottom opposite the long flap,

said short flap including all the material from the other slit in the first-named face to the corresponding slit in the second-named face, said equal flaps beingfolded over the long and short flaps, the said perforations serving to permit adhesive to pass from the inner ply to said equal flaps to secure the latter in position against the overlapped flaps of the outer ply. Y

15. A container made from a tube of material comprising paper and a material impervious to air and moisture laminated together and including-a square bottom folded in from a fold line extending circumferentially of the tube in such a way that the material folded in from each pair of opposed sides overlaps, the folded-in material being slitted on two opposed sides along lines extending from the end of the tube to points re-. moved from the fold line to provide a pair of overlapping flaps which are secured together and secured to other folded-in portions of the bottom whereby to make a sift-proof and moisture-proof bottom for the container.

ALBERT J. STERLING.

Cal 

